Auto-buffering

The Enable auto-buffering option lets you enable the data buffer property for all user-created dynamic attributes on a Galaxy-wide basis, without having to set the data buffer property for individual attributes. Application Server automatically configures buffer when auto-configure buffering is enabled. If your Galaxy includes legacy Field Attributes, data buffering is enabled for these also when buffering for the Galaxy is enabled.

Data buffering ensures that any and all data changes are captured if a given attribute changes its value several times during a single scan cycle. There is no folding of data, which occurs when an accumulation of values of multiple data changes within a single scan are overwritten and only the latest value is stored. This would be the case without buffering.

Even with data buffering enabled, only the final value is propagated to HMI or other user-facing touch points within System Platform, but interim values are historized. If data buffering is not enabled, interim values accumulated within a single scan cycle are not preserved. With data buffering enabled, the entire set of buffered data values is historized along with time and quality (VTQ). The entire set of buffered values can also be viewed within the Object Viewer.

If Galaxy-wide data buffering is not enabled, you can enable buffering for individual attributes that are I/O-enabled. See The I/O Feature for details. The behavior of the buffer property remains the same, whether it is applied across the Galaxy or if it is enabled only for individual attributes.

Note: All user-created attributes are enabled for buffering when auto-configured buffering is enabled, not just those attributes with the I/O feature enabled. With auto-configured buffering enabled, Application Server dynamically creates a buffer for the user-created attributes, even if no values are being buffered.